Struct windows_helpers::ResGuard

pub struct ResGuard<R, S, F>
where
    R: CanInto<S> + TypeKind<TypeKind = CopyType> + Clone,
    S: Clone,
    F: FnOnce(R),
{ /* private fields */ }

Holds a resource and a free-closure that is called when the guard is dropped.

Allows to couple resource acquisition and freeing, while treating the guard as the contained resource and ensuring freeing will happen. When writing the code, it’s also nice to transfer the documentation into everything that has to happen in one go without having to split it into upper and lower or here- and there-code. In a function, Rust’s drop order should ensure that later aquired resources are freed first.

Implementations

impl<R, S, F> ResGuard<R, S, F>

where R: CanInto<S> + TypeKind<TypeKind = CopyType> + Clone, S: Clone, F: FnOnce(R),

pub fn new(resource: R, free: F) -> Self

Should normally not be needed.

pub fn with_acquisition<A, E>(acquire: A, free: F) -> Result<Self, E>

where A: FnOnce() -> Result<R, E>,

For functions that return the resource.

pub fn with_mut_acquisition<A, T, E>(acquire: A, free: F) -> Result<Self, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

For functions that provide the resource by means of an out-parameter.

pub fn two_with_mut_acquisition<A, T, E>( acquire_both: A, free_first: F, free_second: F ) -> Result<(Self, Self), E>

where A: FnOnce(&mut R, &mut R) -> Result<T, E>, R: Default,

For purpose, see Self::two_with_mut_acq_and_close_handle().

impl<R> ResGuard<R, HANDLE, fn(_: R)>

where R: CanInto<HANDLE> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_close_handle<A, E>( acquire: A ) -> Result<ResGuard<R, HANDLE, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HANDLE_CloseHandle.

pub fn with_mut_acq_and_close_handle<A, T, E>( acquire: A ) -> Result<ResGuard<R, HANDLE, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HANDLE_CloseHandle.

impl<R> ResGuard<R, HDC, fn(_: R)>

where R: CanInto<HDC> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_delete_dc<A, E>( acquire: A ) -> Result<ResGuard<R, HDC, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HDC_DeleteDC.

pub fn with_mut_acq_and_delete_dc<A, T, E>( acquire: A ) -> Result<ResGuard<R, HDC, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HDC_DeleteDC.

impl<R> ResGuard<R, HGDIOBJ, fn(_: R)>

where R: CanInto<HGDIOBJ> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_delete_object<A, E>( acquire: A ) -> Result<ResGuard<R, HGDIOBJ, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HGDIOBJ_DeleteObject.

pub fn with_mut_acq_and_delete_object<A, T, E>( acquire: A ) -> Result<ResGuard<R, HGDIOBJ, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HGDIOBJ_DeleteObject.

impl<R> ResGuard<R, HGLOBAL, fn(_: R)>

where R: CanInto<HGLOBAL> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_global_free<A, E>( acquire: A ) -> Result<ResGuard<R, HGLOBAL, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HGLOBAL_GlobalFree.

pub fn with_mut_acq_and_global_free<A, T, E>( acquire: A ) -> Result<ResGuard<R, HGLOBAL, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HGLOBAL_GlobalFree.

impl<R> ResGuard<R, HICON, fn(_: R)>

where R: CanInto<HICON> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_destroy_icon<A, E>( acquire: A ) -> Result<ResGuard<R, HICON, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HICON_DestroyIcon.

pub fn with_mut_acq_and_destroy_icon<A, T, E>( acquire: A ) -> Result<ResGuard<R, HICON, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HICON_DestroyIcon.

impl<R> ResGuard<R, HLOCAL, fn(_: R)>

where R: CanInto<HLOCAL> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_local_free<A, E>( acquire: A ) -> Result<ResGuard<R, HLOCAL, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HLOCAL_LocalFree.

pub fn with_mut_acq_and_local_free<A, T, E>( acquire: A ) -> Result<ResGuard<R, HLOCAL, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HLOCAL_LocalFree.

impl<R> ResGuard<R, HMENU, fn(_: R)>

where R: CanInto<HMENU> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_destroy_menu<A, E>( acquire: A ) -> Result<ResGuard<R, HMENU, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HMENU_DestroyMenu.

pub fn with_mut_acq_and_destroy_menu<A, T, E>( acquire: A ) -> Result<ResGuard<R, HMENU, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HMENU_DestroyMenu.

impl<R> ResGuard<R, HMODULE, fn(_: R)>

where R: CanInto<HMODULE> + TypeKind<TypeKind = CopyType> + Clone,

pub fn with_acq_and_free_library<A, E>( acquire: A ) -> Result<ResGuard<R, HMODULE, fn(_: R)>, E>

where A: FnOnce() -> Result<R, E>,

Activate feature HMODULE_FreeLibrary.

pub fn with_mut_acq_and_free_library<A, T, E>( acquire: A ) -> Result<ResGuard<R, HMODULE, fn(_: R)>, E>

where A: FnOnce(&mut R) -> Result<T, E>, R: Default,

Activate feature HMODULE_FreeLibrary.

impl<R> ResGuard<R, HANDLE, fn(_: R)>

where R: CanInto<HANDLE> + TypeKind<TypeKind = CopyType> + Clone,

pub fn two_with_mut_acq_and_close_handle<A, T, E>( acquire_both: A ) -> Result<(ResGuard<R, HANDLE, fn(_: R)>, ResGuard<R, HANDLE, fn(_: R)>), E>

where A: FnOnce(&mut R, &mut R) -> Result<T, E>, R: Default,

For a function like CreatePipe() that returns two resources at once.

Activate feature HANDLE_CloseHandle.

Trait Implementations

impl<R, S, F> Deref for ResGuard<R, S, F>

where R: CanInto<S> + TypeKind<TypeKind = CopyType> + Clone, S: Clone, F: FnOnce(R),

type Target = R

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<R, S, F> Drop for ResGuard<R, S, F>

where R: CanInto<S> + TypeKind<TypeKind = CopyType> + Clone, S: Clone, F: FnOnce(R),

fn drop(&mut self)

Executes the destructor for this type.